Paul Bonatz and the Search for an Art - Department of Architecture

It lasted until the rise of the Modern Movement till tectonics, called the "poetics of construction" by
Kenneth Frampton (Frampton 1993, 2), took over the role of ornamentation in architecture.
However, the awareness of its significance somehow nearly got lost in architectural history, maybe
because of the great importance that was given to the aspect of functionality. Nevertheless, authors
like Julius Posener (1904-1996) finally rediscovered in Modern Architecture that “the construction,
which works, is not always the construction, which one can see." (Klotz 1986, 28). Posener realised
this phenomenon through the analysis of facades of Mies van der Rohe’s later buildings. These
buildings also stood in the focus of Eduard Sekler’s key essay about the intense relationship
between "Structure, Construction, Tectonics" (Sekler 1965).
Sekler saw tectonics as the visual expression of construction which itself had to be understood as a
particular physical manifestation of the “intangible concept” defined by the structure of an edifice
(Sekler 1965, p. 92). Regarding this definition one easily can see that tectonics should have played
an important role especially for bridges – as structure and construction always are the two dominant
parameters for their design. But, neither Sekler mentioned engineering structures in his text nor did
30 years later Kenneth Frampton, whose widely recognised book about the “Tectonic Culture” in
modern time’s building brought back the idea of tectonics to the world of architectural history
(Frampton 1993). Hence, in the end, both also followed the reduced path that had been laid out
earlier by Sigfried Giedion.
Tectonics and Construction in Engineering – a Complicated Relationship
The fact that architectural theoreticians seemed to ignore the efforts of architects like Paul Bonatz to
transfer the idea of tectonics into structural engineering finds a sort of parallel in the engineer’s
view. Even if architects consulted engineers in bridge building throughout the whole twentieth
century, the idealistic concept that structurally optimised edifices as bridges do not need any
tectonic treatment at all was a widespread thought.
A fascinating case in this field is the comparison of the bridge over the Danube at Leipheim on the
Reichsautobahn between Stuttgart and Munich (Fig.12), designed by Karl Schaechterle, Wayss &
Freytag and Bonatz, with the contemporary bridge over the Arve at Vessy (Fig.13) by one of the
most outstanding engineers of the twentieth century, Robert Maillart (1872-1940). The comparison
of these two bridges (both were based on Maillart’s structural concept for three-hinged arch
bridges) recently was discussed by David P. Billington (Billington 1997, p. 219-20) and originates
in an essay that Maillart himself published in 1938 (Maillart 1938).
But, while Maillart’s biographer Billington mainly came to the conclusion that the bridge over the
Danube stood symptomatic for a German tendency towards a massive appearance, Maillart himself
stressed to have worked with a different approach than did Schaechterle and Bonatz (ibid., p. 292).
In fact, the difference between an economically optimised bridge in a side valley of the mountains
2152